U.S. patent number 6,788,471 [Application Number 10/271,775] was granted by the patent office on 2004-09-07 for projection exposure apparatus for microlithography.
This patent grant is currently assigned to Carl Zeiss Semiconductor Manufacturing Technologies AG. Invention is credited to Wilhelm Ulrich, Christian Wagner.
United States Patent |
6,788,471 |
Wagner , et al. |
September 7, 2004 |
**Please see images for:
( Certificate of Correction ) ** |
Projection exposure apparatus for microlithography
Abstract
The invention relates to a projection exposure apparatus for
microlithography at .lambda.<200 nm. The projection exposure
apparatus for microlithography has a light source with a wavelength
less than 200 nm and a bandwidth, which is less than 0.3 pm,
preferably less than 0.25 pm and greater than 0.1 pm. The
projection exposure apparatus includes an exclusively refractive
projection objective which is made out of a single lens material.
The projection objective provides for a maximum image height in the
range of 12 mm to 25 mm, an image side numerical aperture in the
range of 0.75 up to 0.95 and a monochromatic correction of the
wavefront of rms<15.Salinity. of the wavelength of the light
source.
Inventors: |
Wagner; Christian (Eersel,
NL), Ulrich; Wilhelm (Aalen, DE) |
Assignee: |
Carl Zeiss Semiconductor
Manufacturing Technologies AG (Oberkochen, DE)
|
Family
ID: |
7702835 |
Appl.
No.: |
10/271,775 |
Filed: |
October 17, 2002 |
Foreign Application Priority Data
|
|
|
|
|
Oct 17, 2001 [DE] |
|
|
101 51 309 |
|
Current U.S.
Class: |
359/649; 355/67;
359/355; 362/268 |
Current CPC
Class: |
G03F
7/70058 (20130101); G03F 7/70241 (20130101) |
Current International
Class: |
G03F
7/20 (20060101); G02B 009/00 (); G02B 013/14 ();
G03B 027/54 (); F21V 027/00 () |
Field of
Search: |
;359/355,649,663 ;355/67
;362/268 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
"Lithography with 157 nm lasers" by T. M. Bloomstein et al, J. Vac.
Sci. Technol. B 15(6), Nov./Dec. 1997, pp. 2112 to 2116..
|
Primary Examiner: Spector; David N.
Attorney, Agent or Firm: Ottesen; Walter
Claims
What is claimed is:
1. A projection exposure apparatus for microlithography comprising:
a light source for transmitting light along a beam path at a
wavelength of less than 200 nm and a bandwidth of less than 0.3 pm;
an exclusively refractive projection objective arranged on said
beam path and being made of a single lens material; said projection
objective having a maximum image height in a range of 12 mm to 25
mm and an image side numerical aperture in a range of 0.75 to 0.95;
and, said projection objective being configured to provide a
monochromatic correction of a wavefront to rms<15.Salinity. of
said wavelength of said light source.
2. The projection exposure apparatus of claim 1, further comprising
an illumination system incorporating said light source and
providing for at least one of: increase of the geometrical light
flux, homogenization, variable illumination, variable illumination
aperture, annular aperture, bipole illumination and quadrupole
illumination providing for variable coherence length.
3. The projection exposure apparatus of claim 1, wherein said
projection objective includes at least one aspherical surface.
4. The projection exposure apparatus of claim 3, wherein said
aspherical surface is a convex surface.
5. The projection exposure apparatus of claim 3, wherein said
projection objective comprises a first, a second, a, third, a
fourth and a fifth lens group.
6. The projection exposure apparatus of claim 5, wherein said
second lens group and said fourth lens group have a negative
refraction power and said first lens group includes at least one
lens having an aspherical lens surface.
7. The projection exposure apparatus of claim 6, wherein said
aspherical lens surface is a convex surface.
8. The projection exposure apparatus of claim 5, wherein said
second lens group and said fourth lens group have a negative
refraction power and said third lens group includes at least one
lens having an aspherical lens surface.
9. The projection exposure apparatus of claim 8, wherein said
aspherical lens surface is a convex surface.
10. The projection exposure apparatus of claim 5, wherein said
second lens group and said fourth lens group have a negative
refraction power and said fifth lens group includes a negative lens
having an aspherical lens surface.
11. The projection exposure apparatus of claim 10, wherein said
aspherical lens surface is a convex surface.
12. The projection exposure apparatus of claim 1, wherein lenses
consisting of fluoride material are provided.
13. The projection exposure apparatus of claim 1, wherein said
projection objective provides for a chromatic longitudinal
aberration CHL (in nm/pm) which is less than 5.Salinity. of the
wavelength of the light of the light source.
14. The projection exposure apparatus of claim 1, wherein said
light source provides for light having a wavelength .lambda. of
about 157 nm.
Description
FIELD OF THE INVENTION
The invention relates to a projection exposure apparatus for
microlithography with a light source having a wavelength less than
200 nm and a bandwidth less than 0.3 pm, preferably less than 0.2
pm and with an exclusively refractive projection objective made of
a single lens material.
BACKGROUND OF THE INVENTION
European patent publication 1 037 267 discloses a projection
exposure apparatus for microlithography used for transferring a
mask pattern onto a substrate such as a semiconductor device. The
dimensions of structures which can be generated on the substrate
are limited by dispersion in the optical system of the projection
exposure apparatus. In using light for illumination having a
bandwidth .DELTA..lambda. which is comparatively narrow, the
effects of dispersion can be minimized. European patent publication
1 037 267 teaches that the maximum tolerable bandwidth
.DELTA..lambda. of the light for illumination is proportional to
L/NA.sup.2, with L being the inter object-image distance and NA
denoting the numerical aperture. It is suggested to use F.sub.2
-lasers or YAG lasers as light sources for illumination providing
illumination light having a wavelength shorter than 193 nm and 157
nm, respectively. As an example, in European patent publication 1
037 267, an exclusively spherical projection objective is described
which consists of 27 lenses with NA=0.6, L=1000 mm, magnification
.beta.=-0.25, infinite focal length and maximum image height Y=13.2
mm.
Lithography by means of 157 nm lasers is described in T. M.
Bloomstein et al, J. Vac. Sci. Technol. B 15(6), November/December
1997, p. 2112-2116.
This publication suggests that in lithographic systems using laser
illumination light at .lambda.=157 nm, exclusively refractive
projection objectives could consist of lenses made of a single lens
material. For lithography however the bandwidth of the laser light
should be narrowed as known for lasers providing laser light at
.lambda.=193 nm.
In "Clearing the Hurdles in the 157 nm Race", Phil Ware, Canon
Submicron Focus, Summer 2000, p. 17, several projection objectives
for .lambda.=157 nm are described. For such refractive single
material projection objectives, a narrowing of the bandwidth to
within a range of 0.1 to 0.2 pm is deemed necessary.
U.S. Pat. No. 6,243,206 discloses an illuminating system for
ultraviolet microlithography at 157 nm wavelength. This system has
refractive optical elements made of fluoride material and includes
both a microlens array functioning as an element for increasing the
light conductance value and a honeycomb condenser.
It is well known how to narrow the bandwidth of present day lasers
at .lambda.=193 nm and .lambda.=157 nm. However, the narrower the
bandwidth of the laser light, the greater the loss in efficiency of
the corresponding laser and the higher the production costs of such
an apparatus.
In pure quartz glass objectives for .lambda.=248 nm and achromatic
objectives for .lambda.=193 nm, numerical apertures of 0.7 to 0.9
are state of the art.
SUMMARY OF THE INVENTION
In the field of microlithography, enhanced resolution can only be
achieved by reducing the wavelength and only if a high image side
numerical aperture in the order of magnitude of 0.7 to 0.9 is
maintained.
The object of the present invention is to provide a projection
exposure apparatus as described hereinafter which allows for a gain
in resolution while affording the advantages of illumination at a
reduced wavelength.
This object is achieved by a projection exposure apparatus for
microlithography which includes a light source having a wavelength
of less than 200 nm and a bandwidth of less than 0.3 pm, preferably
less than 0.25 pm, and greater than 0.1 pm; and, an exclusively
refractive projection objective made of a single lens material. The
projection objective has: a maximum image height in the range of 12
mm up to 25 mm; an image side numerical aperture in the range of
0.75 to 0.95; and, a monochromatic correction of the wavefront to
rms<15.Salinity. of the wavelength of the light source.
The parameters of the optics of such a projection apparatus allow
for the imaging quality achieved at higher wavelengths or in
achromatic 193 nm projection exposure apparatuses.
The large image field as represented by the image height allows for
a high throughput and for correspondence to the exposure field of
other machines operating under less demanding structural
requirements. Only with such a high numerical aperture is it
possible to achieve a gain in resolution using light of wavelength
.lambda.=157 nm for illumination compared to light for illumination
at wavelength .lambda.193 nm. The resolution which can be achieved
is proportional to the ratio of the wavelength .lambda. of the
illumination light and the image side numerical aperture NA, that
is .lambda./NA. For .lambda.=193 nm and NA=0.9, this ratio is 193
nm/0.9=214 nm, for .lambda.=157 nm and NA=0.6, the ratio is 157
nm/0.6=261 nm, which is remarkably greater, and for .lambda.=157 nm
and NA=0.75, the ratio is 157 nm/0.75=209 nm, which corresponds
approximately to the ratio at .lambda.=193 nm. This means that for
the range of the numerical aperture of 0.75 to 0.95, a gain in
resolution is possible by using illumination light having
wavelength .lambda.=157 nm as compared to illumination light having
wavelength .lambda.=193 nm. Because of the high numerical aperture,
the quality of imaging is increased as compared to state of the art
systems especially at .lambda.=193 nm.
The high quality correction of the projection objective to a
monochromatic image plane wavefront error of rms<15.Salinity.
ensures that, all over the image field, use can be made of the high
resolution, which is achieved because of the small wavelength and
the high aperture. Furthermore, this allows for form-correct
undistorted imaging all over the image plane. For comparison, in
the field of optics, a system having an image error, the magnitude
of which corresponds to the ratio of the wavelength and the image
side numerical aperture, is usually considered to be limited by
diffraction. It should be noted that this error is up to five
hundred times greater than with the projection exposure apparatus
of the present invention.
In a preferred embodiment of the invention there is an illumination
system providing for an increase of the geometrical light flux,
that means an increase of the etendue. Preferably also
homogenization and variable illumination aperture are provided. The
projection illumination apparatus may provide for an annular
aperture, a quadrupolar illumination as well as a variable
coherence length. Such projection exposure apparatus allows for the
best structure-related resolution. Without such an illumination
system, a projection exposure apparatus at 157 nm or 193 nm does
not provide advantages for many types of structures with respect to
conventional projection exposure apparatuses.
In another preferred embodiment of the present invention, there is
at least one lens in the projection objective having an aspherical
surface. Lenses with an aspherical lens surface allow a reduction
of the path length which the light has to travel through the
optical elements of an objective. This reduces not only absorption
and hence dissipation of energy in the lens material but also
allows less lens material to be used and reduces the number of
lenses required in a projection objective. This is of interest in
view of the extraordinarily high costs of the lens material, in
particular the costs of CaF.sub.2. Furthermore, these aspherical
surfaces allow for a relatively small number of lenses or
refractive surfaces such that also reflection losses and thus
production costs are reduced.
Preferably fluorides are used as lens material. Such material is
particularly apt for illumination with light at wavelength
.lambda.=157 nm. Preferably, CaF.sub.2 may be used but lenses could
also be made of BaF.sub.2 or LiF.sub.2. In a preferred embodiment,
single crystalline fluorides are used as optical elements in the
projection exposure apparatus which are chosen for having highest
transparency in the wavelength range of the illumination light
which is used. Besides fluorides, also quartz glass could be used
as a lens material, in particular at wavelength .lambda.=193 nm. At
lower wavelengths also fluoride-doped quartz glass could also be
used.
Preferably the chromatic longitudinal aberration is chosen to be
less than 5.Salinity. of the wavelength of the light of the light
source so the order of magnitude of the chromatic error does not
exceed the order of the monochromatic error. Then the chromatic
error is not significantly detrimental to the resolution of the
projection exposure apparatus. For a given dispersion of the lens
material, this is achieved by reducing the bandwidth of the light
source and by optimizing the bandwidth of the projection
objective.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described with reference to the drawings
wherein:
FIG. 1 is a schematic view of a projection exposure apparatus;
FIG. 2 is a sectional view of the lens arrangement of a first
projection objective embodiment;
FIG. 3 is a sectional view of the lens arrangement of a second
projection objective embodiment; and
FIG. 4 is a sectional view of the lens arrangement of a third
projection objective embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION
The projection exposure apparatus shown in FIG. 1 has a light
source 1 providing illumination light having a wavelength below 200
nm. The light source includes an ArF-laser 11 of wavelength
.lambda.=193 nm. As an alternative to the ArF-laser 11, a F.sub.2
-laser may be used providing illumination light at wavelength
.lambda.=157 nm. The projection exposure apparatus further includes
a unit 12 for narrowing of the laser bandwidth of the laser 11.
This unit 12 may be integrated in the laser resonator and provides
a laser bandwidth of below 0.3 pm, preferably below 0.25 pm.
Extreme narrowing of the laser bandwidth to values below 0.1 pm is
not required.
The maximum tolerable bandwidth of the illumination light used in
present projection exposure apparatus is deduced from the
requirement that the limiting chromatic longitudinal error CHL is
smaller than half a Rayleigh unit RE, that is, ##EQU1##
The bandwidth .DELTA..lambda. follows from the ratio of
CHL(.DELTA..lambda.) and the chromatic longitudinal error of the
objective design normalized to 1 nm, that is, CHL(/nm):
##EQU2##
The UV-light is guided to the illumination system 3 via a laser
beam line 2 coupled to the light source 1. For allowing optimum
projection microlithography with the laser light, the illumination
system includes means 31 for enhancing the divergence of the
illuminating light. These means 31 for enhancing the divergence of
the illumination light are formed by one or more optical elements.
These elements are patterned and include refractive or diffractive
microlenses. As an alternative to the microlenses, a scattering
disk may be used for enlarging divergence of the illumination
light.
The means for enhancing divergence of the illumination light is
followed by means for setting the spatial coherence a of the
illumination light and means for setting the type of illumination
as, for example, annular, dipolar or quadrupolar illumination.
These means include an integrated zoom-axicon group 32.
Alternatively some other corresponding transforming means could be
included. It is required that these means obstruct as little light
as possible.
The integrated zoom-axicon group 32 is followed by a
homogenizer-lightmixer-integrator in form of a honeycomb condenser
33. As an alternative, a glass bar, preferably out of crystalline
fluoride or a corresponding mirror box may be used. The
homogenizer-lightmixer-integrator is designed for short optical
pathlengths in the transparent material.
An objective 34 generates a border-sharp image of a reticle mask
(REMA) 35 on the reticle 4 where the homogeneity of the light
intensity is greatest.
The reticle 4 is illuminated in a telecentric way. Preferably there
is fine adjustment of the reticle 4 to the telecentric properties
of the projection objective 5 as explained below. The substrate 6,
which is to be exposed, is positioned below the projection
objective. For example, such substrate may be a wafer for
manufacturing microelectronic devices. However it is noted that the
substrate could also be formed by other elements which are to be
microstructured as, for example, microoptical or micromechanical
devices.
The reticle 4 and the substrate 6 are aligned with respect to the
projection objective 5 and the illumination system 3 in a highly
precise way. They are moved precisely in response to
step-and-repeat, step-and-scan or stitching.
Due to the high absorption of the UV-light of below 200 nm, the
light path is held free from strongly absorbing materials as, for
example, water vapor. Because of the high UV-light power, the
atmosphere is kept free from O.sub.2 in order to avoid
photochemical corrosion. This is done by providing a special
atmosphere around the optics. Such a special atmosphere may include
nitrogen or helium as appropriate gases or a vacuum.
In the following, different embodiments for the projection
objective 5 in FIG. 1 are presented. All these objectives are
refractive objectives and consist of lenses made out of a single
lens material.
FIG. 2 shows a first projection objective embodiment. The technical
design data for this objective are given in TABLE 1. The projection
objective is characterized by the following parameters:
magnification: .beta. = -1/4 image side numerical aperture: NA =
0.75 image field: 17 .times. 6 mm.sup.2 (for stitching)
inter-object image distance: 1000 mm operating wavelength (F.sub.2
-laser): 157 nm maximum rms of the monochromatic wavefront 10
m.lambda. (1.57 nm) error over the total image field: chromatic
longitudinal aberration (1 nm): 0.64 pm/nm useable laser bandwidth:
0.22 pm resolution: .about.100 nm largest lens diameter: 225 mm
The given resolution res is calculated from res=K.sub.1.lambda./NA,
where K.sub.1 =0.5 denotes a process parameter, .lambda. is the
wavelength of the illumination light and NA is the image side
numerical aperture.
Referring to FIG. 2, between the object plane Ob and the image
plane Im, the objective has five lens groups. The first lens group
includes lenses 101-106. The second lens group has lenses 107 and
108. The third lens group includes lenses 109-114. The fourth lens
group has lenses 115 and 116. The fifth lens group includes lenses
117 to 128. The objective has an end plate 129 which is
plane-parallel. All these optical elements consist of single
crystalline CaF.sub.2. The objective corresponds to a basic design
for microlithography projection objectives. This design includes
two beam waists and provides for several negative lenses (101,
107-109 and 114-117) at these beam waists. On the object end, there
is a biconcave lens 101. This biconcave lens 101 is the first lens
in the lens arrangement. This lens has a working distance to the
object plane which is sufficiently large.
The system aperture AS lies in the region of the third extended
antinode, where a negative meniscus lens 123 is provided.
Three aspherical surfaces of the lenses 105, 109, 127 allow for
enlarging the correction degrees of freedom so that a high imaging
quality can be achieved with a limited number of lenses.
The projection objective includes two aspherical lens surfaces 105,
109 in the region of the first antinode and the first waist and
both face toward the image plane. The projection objective further
includes another aspherical surface, which as seen from the image
end of the objective, is the last aspherical surface 127 of the
objective. This aspherical surface 127 faces away from the image
plane. All these aspherical surfaces are convex surfaces. Such
convex lens surfaces are more easy to manufacture and to examine as
compared to concave lens surfaces.
It is to be noted that there is no asphere in the region of the
system aperture AS. of course, more aspherical surfaces of lenses
may be provided. However, due to the much greater effort which is
needed with regard to manufacturing and examination, as few
aspheres as possible should be used.
FIG. 3 shows a second objective embodiment. The technical design
data for this objective are given in TABLE 2.
Between the object plane Ob and the image plane Im, the objective
also has five lens groups. The first lens group includes lenses 201
to 206. The second lens group has lenses 207 and 208. The third
lens group includes lenses 209 to 214. The fourth lens group has
lenses 215 and 216. The fifth lens group includes lenses 217 to
228. The objective has an end plate 229 which is plane-parallel.
The second projection objective is of the same quality as the first
projection objective. However a larger image field is provided.
This objective still may be used for classical step-and-scan
processes. The parameters of the second objective are as
follows:
magnification: .beta. = -1/4 image side numerical aperture: NA =
0.75 image field: 26 .times. 8 mm.sup.2 inter-object image
distance: 1000 mm operating wavelength (F.sub.2 -laser): 157 nm
maximum rms of the monochromatic wavefront 11 m.lambda. error over
the total image field: chromatic longitudinal aberration (1 nm):
0.72 .mu.m/nm useable laser bandwidth: 0.19 pm resolution:
.about.100 nm largest lens diameter: 235 mm
FIG. 4 shows a third objective embodiment. Between the object plane
Ob and the image plane Im, the objective has five lens groups. The
first lens group includes lenses 301-306. The second lens group has
lenses 307 and 308. The third lens group includes lenses 309-314.
The fourth lens group has lenses 315 and 316. The fifth lens group
includes lenses 317 to 328. The technical design data for this
objective are given in TABLE 3. This projection objective is a
switching objective where the inter-object image distance is
reduced to 2/3 as compared with the objectives shown in FIGS. 2 and
3. Consequently, absorption losses for this objective are
correspondingly reduced because of the shorter optical light path
through the lenses. Furthermore, less CaF.sub.2 -material for the
lenses is needed as the material required is reduced to less than
half of the volume for the objectives shown in FIGS. 2 and 3.
Therefore, this objective design allows for a decisive reduction in
production cost.
The parameters of the projection objective shown in FIG. 4 are
given below:
magnification: .beta. = -1/4 image side numerical aperture: NA =
0.75 image field: 17 .times. 6 mm.sup.2 inter-object image
(distance): 663 mm operating wavelength (F.sub.2 -laser): 157 nm
maximum rms of the monochromatic wavefront 7 m.lambda. error over
the total image field:
The sectional view of the lens arrangement of the second and third
projection objective embodiment are very similar. In a first
approximation, it can be said, that the third embodiment is just a
scaled-down version of the second embodiment. The third embodiment
is characterized by a relatively long free drift length in the area
of the second antinode of the optical beam path. Apart from this,
the characteristics of the first embodiment are also met in the
third embodiment.
Overall, the invention shows, that it is possible to use projection
objectives which are exclusively refractive and which are not made
achromatic by means of two different lens materials for carrying
out microlithography at wavelength .lambda.=157 nm and also at
wavelength .lambda.=193 nm while working at standard laser light
bandwidths widely used in the field of microlithography. It is
possible to build projection exposure apparatuses having the
required high image side numerical aperture. Appropriate
illumination systems providing for the necessary flexibility in
terms of different illumination modes are available. A diminishing
of the image field in terms of stitching allows saving of expensive
lens material and makes the construction less expensive.
It is understood that the foregoing description is that of the
preferred embodiments of the invention and that various changes and
modifications may be made thereto without departing from the spirit
and scope of the invention as defined in the appended claims.
TABLE 1 157 nm: 4.times./0.75 17 .times. 6 mm USED ELEMENT RADIUS
RADIUS DIAMETER NUMBER FRONT BACK THICKNESS FRONT OB INF 21.2160
80.5345 7.2553 101 -115.7621 CC 213.1810 CC 4.6410 80.5443 4.2404
102 792.2783 CX -136.4601 CX 12.3286 90.2142 0.3315 103 1067.0745
CX -181.7748 CX 11.0939 98.4446 0.3315 104 378.1984 CX -265.5741 CX
11.4883 102.3597 0.3315 105 224.6510 CX A (1) 12.9746 101.2653
0.3315 106 133.5672 CX 71.0135 CC 13.6914 92.4091 15.6747 107
-337.6630 CC 109.9077 CC 4.6410 80.0859 14.0503 108 -131.6748 CC
150.8187 CC 4.6410 78.5863 20.8572 109 -104.0376 CC A (2) 4.6410
89.9352 6.1949 110 -143.8077 CC -93.3047 CX 10.1477 102.5910 0.6281
111 5969.0673 CX -134.8494 CX 19.7977 126.6423 0.3315 112 263.7742
CX -215.7957 CX 24.3807 140.6339 48.1858 113 113.7579 CX -2952.2070
CX 20.6518 119.8425 1.8185 114 122.7460 CX 75.1878 CC 14.5159
103.7065 19.3036 115 -201.8765 CC 212.7200 CC 4.6410 86.2873
12.0563 116 -119.9368 CC 140.1595 CC 4.6410 82.0743 6.4165 117
-75.1970 CC 2139.9405 CC 4.6924 87.3250 8.1650 118 -272.6518 CC
-115.0768 CX 12.5284 107.0978 0.4687 119 -5512.2722 CC -144.7103 CX
23.6457 126.2784 0.4584 120 970.7047 CX -274.1440 CX 14.9265
141.2732 -16.5750 APERTURE STOP 139.9019 21.7740 145.4872 1.9890
121 571.8065 CX -697.0709 CX 11.7771 148.1741 0.3315 122 301.5827
CX -274.0065 CX 22.9521 150.2673 10.8509 123 -146.5289 CC -353.9458
CX 20.8507 149.5282 12.8151 124 -213.2199 CC -145.9024 CX 11.9362
153.2562 0.3321 125 112.5118 CX 289.2105 CC 19.4075 138.7339 0.5204
126 88.5495 CX 163.9744 CC 18.2007 121.4501 9.5730 127 A (3)
275.3482 CC 8.0308 113.7185 0.6374 128 90.0474 CX 198.6691 CC
50.2333 93.0110 4.0611 129 INF INF 1.9890 38.3454 IMAGE DISTANCE =
7.9560 IM INF 18.0000 ASPHERICAL CONSTANT ##EQU3## ASPHERIC CURVE K
A B C D A (1) -0.00266392 0.000000 -1.16728E-07 -4.98736E-12
1.05871E-15 -1.10882E-19 A (2) -0.00302040 4.403490 -1.93335E-08
-5.16149E-12 1.76471E-17 -8.44115E-20 A (3) 0.00157186 0.000000
-6.86103E-09 -3.01927E-12 4.16805E-16 -2.20170E-20
TABLE 2 157 nm: 4.times./0.75 26 .times. 8 mm USED ELEMENT RADIUS
RADIUS DIAMETER NUMBER FRONT BACK THICKNESS FRONT OB INF 32.0000
121.6828 10.9432 201 -174.6035 CC 321.5400 CC 7.0000 121.6828
6.3958 202 1194.9899 CX -205.8222 CX 18.5952 136.2957 0.5000 203
1609.4638 CX -274.1701 CX 16.7329 148.7297 0.5000 204 570.4350 CX
-400.5643 CX 17.3278 154.6429 0.5000 205 338.8401 CX A (1) 19.5696
152.9796 0.5000 206 201.4588 CX 107.1093 CC 20.6507 139.5639
23.6421 207 -509.2957 CC 165.7732 CC 7.0000 120.9462 21.1920 208
-198.6045 CC 227.4791 CC 7.0000 118.6559 31.4588 209 -156.9194 CC A
(2) 7.0000 135.7457 9.3437 210 -216.9046 CC -140.7311 CX 15.3058
154.8468 0.9474 211 9003.1181 CX -203.3927 CX 29.8608 191.1726
0.5000 212 397.8494 CX -325.4837 CX 36.7732 212.2835 72.6784 213
171.5806 CX -4452.8009 CX 31.1490 180.8390 2.7428 214 185.1372 CX
113.4055 CC 21.8943 156.4745 29.1156 215 -304.4895 CC 320.8446 CC
7.0000 130.1909 18.1845 216 -180.9001 CC 211.4019 CC 7.0000
123.8256 39.8440 217 -113.4193 CC 3227.6629 CC 7.0775 131.7270
12.3152 218 -411.2396 CC -173.5699 CX 18.8966 161.5430 0.7069 219
-8314.1361 CC -218.2659 CX 35.6647 190.4642 0.6914 220 1464.1097 CX
-413.4902 CX 22.5136 213.0816 -25.0000 APERTURE STOP 211.0134
32.8416 219.4460 3.0000 221 862.4532 CX -1051.3889 CX 17.7633
223.5023 0.5000 222 454.8759 CX -413.2828 CX 34.6186 226.6665
16.3664 223 -221.0089 CC -533.8549 CX 31.4490 225.5555 19.3290 224
-321.5987 CC -220.0639 CX 18.0032 231.1908 0.5008 225 169.7010 CX
436.2150 CC 29.2723 209.2933 0.7849 226 133.5588 CX 247.3219 CC
27.4520 183.2223 14.4389 227 A (3) 415.3065 CC 12.1128 171.5813 228
135.8181 CX 299.6517 CC 75.7667 140.3340 6.1253 229 INF INF 3.0000
57.8902 IMAGE DISTANCE = 12.0000 IM INF 27.2000 ASPHERICAL CONSTANT
##EQU4## ASPHERIC CURVE K A B C D A (1) -0.00176618 0.000000
-3.40187E-08 -6.38908E-13 5.96171E-17 -2.74461E-21 A (2)
-0.00200252 4.403490 -5.63445E-09 -6.61216E-13 9.93728E-19
-2.08941E-21 A (3) 0.00104214 0.000000 -1.99954E-09 -3.86786E-13
2.34708E-17 -5.44979E-22
TABLE 3 157 nm: 4.times./0.75 17 .times. 6 mm USED ELEMENT RADIUS
RADIUS DIAMETER NUMBER FRONT BACK THICKNESS FRONT OB INF 32.0000
84.8858 6.8417 301 -135.4093 CC 229.3553 CC 7.0368 84.8926 8.9677
302 -587.1142 CC -189.7989 CX 24.1492 96.6246 0.5238 303 970.0801
CX -192.3938 CX 16.5734 119.5385 0.5000 304 529.1899 CX -311.9989
CX 14.9339 127.0740 0.5000 305 349.2830 CX A (1) 57.7213 127.6292
0.5000 306 95.5355 CX 80.0780 CC 7.4216 106.0867 28.0759 307
-168.2831 CC 152.9631 CC 7.1651 96.9080 21.9848 308 -509.7405 CC
170.3994 CC 7.3791 97.6597 30.5973 309 -163.7568 CC A (2) 7.4717
111.4582 8.7087 310 -191.7537 CC -132.1552 CX 15.4691 123.9992
0.7751 311 -3068.5173 CC -207.2864 CX 30.2084 145.3721 1.7561 312
452.9540 CX -302.0775 CX 50.9848 161.9745 15.0782 313 184.2073 CX
-852.4844 CX 27.4056 156.8187 2.0300 314 193.6735 CX 104.8016 CC
20.4756 138.3805 25.5897 315 -267.6202 CC 389.1276 CC 7.0000
116.6552 13.8184 316 -209.6258 CC 229.3549 CC 9.8674 113.3445
39.3155 317 -112.5355 CC 1428.0917 CC 7.0498 123.7205 12.1163 318
-513.9830 CC -177.1624 CX 18.8131 152.8362 0.5025 319 -6367.0019 CC
-217.2489 CX 35.7995 177.7169 1.4058 320 10263.8608 CX -383.6591 CX
28.1866 197.5246 0.1919 APERTURE STOP 202.8911 31.5278 212.0771
3.000 321 3132.5342 CX -826.3717 CX 14.8348 213.8222 5.5342 322
365.2260 CX -371.2824 CX 38.0908 220.1417 15.2812 323 -210.6493 CC
-403.5697 CX 8.2553 218.9190 16.7168 324 -278.1561 CC -213.3805 CX
34.9977 220.1415 0.8777 325 170.4222 CX 474.9380 CC 28.2159
200.4015 0.5616 326 135.3877 CX 232.6450 CC 27.1639 175.2321
13.7033 327 A (3) 406.4696 CC 11.5043 159.6505 0.5322 328 131.3181
CX 286.5078 CC 75.6193 131.7867 5.6921 329 INF INF 3.0000 48.6905
12.0003 IM INF 18.0000 ASPHERICAL CONSTANT ##EQU5## ASPHERIC CURVE
K A B C D A (1) -0.00442028 0.000000 -4.53266E-08 1.67151E-12
-4.93581E-18 -1.68355E-21 A (2) -0.00223038 4.403490 1.38023E-08
-2.44399E-12 1.81046E-17 -7.23412E-21 A (3) 0.00127570 0.000000
-2.95475E-09 -3.47798E-13 1.98122E-17 -4.57061E-22
* * * * *